RT930turbo

Have you pulled the codes to see if you are continuing to get camshaft timing faults?

deilenberger

Indeed - if you have any intention of DIY maintenance on the Cayenne - then two things are really required:

1, A Porsche capable code reader,. This isn't just an OBD-II reader, it's one that has software that can read fault codes that are stored in modules (aka computers) scattered around the Cayenne. You might find a used Durametric for $200 or so, it requires a windows PC to use (laptop being best), or a iCarScan (retail around $169 - used - maybe $100?). This will let you know what the car thinks is wrong. You can then post those codes and descriptions here and see if anyone is familiar with them. The iCarScan has a feature that it will do a Google search for any code found - not surprisingly many of the returns from the search are found right here on RennList.

2. A subscription to AllDataDIY - with a discount code (there are always discount codes) the cost is about $15/year. Most people find it worth every penny. Think of it as the factory manual on line.

deilenberger

If you poke around on this forum enough you'll find a few threads on the Variocam solenoids where the in-line screens are addressed.

I don't know if the cam sensors are the issue - you haven't gathered enough data to make an intelligent/informed decision. If you had a code/Porsche diagnostics tool - you could make a fairly quick determination if the problem is being caused by mistimed camshafts. The challenge then is to determine what's causing the mistiming. You will be able to read the output of the cam sensors - if it reads a clean signal - it's not the sensors, which pretty much leaves the control solenoids or screen/filter being clogged up.

The big advantage of having diagnostic info at hand is - it avoids the shotgun approach to fixing a car. The shotgun approach is where you react to any post made about a similar problem by replacing parts that were replaced by the other person who posted. The thing is - the last part you or anyone else replaces is always the one that's the problem, but it can be quite costly getting to that last part. Diagnostics gives you a shortcut to what part it might be.

Daren Dozier

deilenberger
I really appreciated your input... I have not been on Rennlist in some time now. I did get a scanner and was able to pull some codes. Meanwhile... I have replaced all of the plugs, coil packs (Beru) and both of the cam sensors. Found a pretty bad vacuum leak at the firewall connection hose while removing the intake manifold. The 955 S ran great all summer and now feels like it is on its last leg for some reason. I am getting a P0202 P0205 P0206 which would indicate that these injectors are having a wiring harness issue... I have put a ohm test on each of the injectors and each are at 13.x with < .8 difference between them. I checked the harness and found cracks in the wires about an inch away from the connectors. They seem very brittle... I also tried a voltage test on each and if I touch to both terminals in the connector I get 8.5 volts? If I connect to ground and go to one side of the terminal I get 8.5 the other side I get 3.5? The car runs like crap right now... I can't even get to the store in it... Any ideas?

deilenberger

Daren, interesting. It sounds as if the ground is floating going to the injectors. I don't have a diagram for the 955/957 fuel injection - but two different schemes are usually used on injectors. On some engines - the injector is grounded on one side of the coil, and the switching voltage (positive side) is pulsed by the ECU. On other engines - some of them have 12.6V (positive) continuously to one side of the injectors and the other side is taken to ground via the ECU when the injector is supposed to fire.

What is curious is - your seeing voltage relative to ground on both sides of the coil. And if you measure voltage across the injector coil - you see 8.5V, but you also see this same voltage relative to ground.

What would I do - I'd try to repair the brittle wiring. The injector plugs are fairly standard, and in the US you can buy replacement plugs with pigtails of wire coming out of them. These could be spliced into the wiring at a point where the insulation is intact. Stores such as NAPA typically carry these sort of connectors. Once that was done if there are still running issues - I'd try to track down the ground points for the injector harness, and make sure they're clean and tight.

Good luck..